Improvement in drilling-machines



-H. MARTIN.

Drilling-Machines.

No 138 57o'. Patentedma,y 61g73.

UNITED STATES PATENT OFFICE.

HENRY MARTIN, OF DUNCAN, PENNSYLVANIA.

IMPROVEMENT IN DRAlLLlNG-MACHINES.

Specification forming part of Letters Patent No. 138,570, dated May 6, 1873 application filed 1 l February 21, 1873.

To all whom it may concern:

Be it known that I, HENRY MARTIN, of

A Duncan, in the county of Allegheny and State of Pennsylvania, have invented a new and Improved Portable Drilling-Press, of which the following is a specification:

My invent-ion consists ofa cylindrical standard having a base-plate adapted to be bolted or clamped on a bench, platform, or other support, on which standard is a horizontal arxn capable of shifting up and down and swinging around, which carries a sliding head and an adjusting-screw to shift the head toward or from the standard; and the sliding head carries a vertical feedscrew with a socket in the lower end, in which the upper end of the handdrill brace is centered to hold it and feed the drill, the whole comprising a simple and cheap substitute for the common ratchet-drill and its adjuncts, by which the work can be done many times faster than with the ratchet.

to be drilled. The base-plate is also adapted for securing the standard to the support by clamps D. E is the horizontal arin for supporting the feed and centering screw F. Itis tted on the standard at one end by a hole in it, through which the standard passes snugly, but so that the arm can bef-shifted up and down and turned around and it is provided with a binding-screw, G, by which it tis fastened whenever it is required. H iswth'e headv block, in which the screw F is mounted. It is fitted on'the arm E in ways I to slide along the arm for adjusting the screw over the Work, and provided with an adjusting-screw, K; also with clamp-screws L for binding it firmly against the arm, so as not'toshake or tumble while holding the drill-crank. This feedscrew has a little conical socket, `\M, at the lower end, in which the conical end N of the top of the drill-crank O is fitted to be centered, confined, and adjusted to feed the drill as the work progresses.

This contrivance affords a very simple press for hand-drillin g, capable of adjusting the drill in various and wide ranges.

Having thus described my invention, Iclaixn as new'and desire to secure by Letters Patentlhe tube A, slotted plate B C, arm E, endsocketed centering-screw F, sliding head-block H, and screws G K L, combined as described, said parts being put together and taken apart, as set forth, so as to make an easily-portable hand-drill.

HENRY MARTIN.

Witnesses JOSEPH SNYDER, R. W. WILEY. 

